Mold: Questions and Answers
Excerpted from the U.S Department of Health and Human Services, Centers for Disease Control.
I heard about "toxic molds" that grow in homes and other buildings. Should I be concerned about a serious health risk to me and my family?
Certain molds can produce toxins. There is always a little mold everywhere - in the air and on many surfaces. There are very few reports that molds found inside homes can cause unique or rare health conditions such as breathing concerns or memory loss. These case reports are rare. A common-sense approach should be used for any mold contamination existing inside buildings and homes. The common health concerns from molds include hay fever-like allergic symptoms. Certain individuals with chronic respiratory disease (chronic obstructive pulmonary disorder, asthma) may experience difficulty breathing. Individuals with immune suppression may be at increased risk for infection from molds. If you or your family members have these conditions, a qualified medical clinician should be consulted for diagnosis and treatment. For the most part, one should take routine measures to prevent mold growth in the home.
How common is mold, in buildings?
Molds are very common in buildings and homes and will grow anywhere indoors where there is moisture. The most common indoor molds are Cladosporium, Penicillium, Aspergillus, and Alternaria.
How do molds get in the indoor environment and how do they grow?
Mold spores occur in the indoor and outdoor environments. Mold spores may enter your house from the outside through open doorways, windows, and heating, ventilation, and air conditioning systems with outdoor air intakes. Mold spores in the air outside also attach themselves to people, animals, clothing, shoes, bags, and pets that may carry mold indoors.
When mold spores drop on places where there is a lot of moisture, such as where leakage may have occurred in roofs, pipes, walls, plant pots, or where there has been flooding, they will grow. Many building materials encourage mold to grow. Wet cellulose materials, including paper and paper products, cardboard, ceiling tiles, wood, and wood products, are particularly conducive for the growth of some molds. Other materials such as dust, paints, wallpaper, insulation materials, drywall, carpet, fabric, and upholstery, commonly support mold growth.
Is it important to know what kind of mold I have?
NO - It is not necessary to determine what type of mold you may have. All molds should be treated the same with respect to potential health risks and removal.
Are there any times where people should leave a home or other building because of mold?
These decisions have to be made individually. If you believe you are ill because of exposure to mold in a building, you should consult your physician to determine the appropriate action to take.
Who are the people who are most at risk for health problems associated with exposure to mold?
People with allergies may be more sensitive to molds. People with immune suppression or underlying lung disease are more susceptible to fungal infections.
How do you know if you have a mold problem.
Large amounts of mold can usually be seen or smelled.
What are the possible health effects of mold in buildings and homes?
Mold exposure does not always present a health problem indoors; however, some people are sensitive to molds. These people may experience symptoms such as nasal stuffiness, eye irritation, sneezing, or skin irritation when exposed to molds. Some people may have more severe reactions to molds. Severe reactions may occur among workers exposed to large amounts of molds in occupational settings, such as farmers working around moldy hay. Severe reactions may include fever and shortness of breath. People with weakened immune systems and chronic lung diseases are at increased risk and may develop fungal infections in their lungs.
How do you get the mold out of buildings, including homes, schools, and places of employment?
Mold growth can be removed from hard surfaces with commercial products, soap and water, or a bleach solution of no more than 1 cup of bleach in 1 gallon of water.
- Always follow the manufacturer's instructions when using bleach or other cleaning products.
- Never mix bleach with ammonia or other household cleaners. Mixing bleach with ammonia or other cleaning products will produce dangerous, toxic fumes.
- Open windows and doors to provide fresh air.
- Wear non-porous gloves and protective eye wear.
- If the area to be cleaned is more than 10 square feet, consult the U.S. Environmental Protection Agency (EPA) guide titled Mold Remediations in Schools and Commercial Buildings. Although focused on schools and commercial buildings, this document also applies to other building types. you can get it free by calling the EPA Indoor Air Quality Information Clearinghouse at (800) 438-4318, or by going to the EPA web site.
How do you keep mold out of buildings and homes?
As part of routine building maintenance, buildings should be inspected for evidence of water damage and visible mold. The conditions causing mold (such as water leaks, condensation, infiltration, or flooding) should be corrected to prevent mold from growing.
Mold Prevention Tips
- Keep the humidity level in your home between 40% and 60%. Use an air conditioner or a dehumidifier during humid months and in damp spaces, like basements.
- Be sure your home has enough ventilation. Use exhaust fans which vent outside your home in the kitchen and bathroom. Make sure your clothes dryer vents outside your home.
- Fix any leaks in your home's roof, walls, or plumbing so mold does not have moisture to grow.
- Clean up and dry out your home thoroughly and quickly (within 24-48 hours) after flooding.
- Add mold inhibitors to paints before painting.
- Clean bathrooms with mold-killing products.
- Remove or replace carpets and upholstery that have been soaked and cannot be dried promptly. Consider not using carpet in rooms or areas like bathrooms or basements that may have a lot of moisture.
For More Information
- Centers for Disease Control and Prevention: Mold Information
- EPA: A Brief Guide to Mold, Moisture, and Your Home